My guess is exactly because there are oils in it, but perhaps not for the reason that this discussion was originally headed.
Polymer sealants last longer AND oil-based waxes look better, right? This is nothing new.
What is a polymer? It's a very long chain of carbon molecules. The building blocks of polymers are what? OILS.
If you have ever fealt or touched pure, emulsified polymer it is slippery beyond belief and you CAN NOT wash it off very easily at all. We use a trick if you get it on your hands or tools and break it down with good old fashion table salt.
I sell polymers. When ship them often times in 300 gallon plastic totes. As the totes sit, the oil-solvent, comes out of solution and floats to the top. It separates out. You have to re-blend them all the time.
We also have emulsified polymers that are water-based. That's right....emulsified polymers in water. That is a newer concept.
Technically speaking, an emulsion is not a solution and therfore the oil is not really a solvent, but a carrier. (now we are getting out of control).
What I suspect is that products like NXT also use oil-based carriers or solvants. In some cases, there may even be added agents that work to keep the product from separating.
If you were to pour some NXT in a glass, I wonder if it would separate. if so, and you poured the oil off the top, I suspect that the product durability would improve, but the shine would not be as good.
So, to answer your question, I suspect that NXT shines better that other "polymers" but does not last as long, because it has more oils in it that other similar products.
But, I could be WRONG.